In this paper, I describe a particular physical arrangement of a computer
system, which I call `WearComp'.
It has the following characteristics[1]

eudaemonic criterion:
The computational apparatus is situated in a manner
that makes it part of what the highly-mobile user considers himself or
herself,
and in a manner that others also regard as part of the user.
Thus it is not tethered to an AC outlet, desktop, or the like,
nor is it a separate object, or collection of separate objects being
carried by the user.

It is often sufficient that the interface (input and output)
alone satisfy this criterion so that some of the computational
resources can be remotely located if desired.

existential criterion:
The computational capability
is controllable by the user. This control need not
require conscious thought or effort,
but the locus of control must be such that
it is within the user's domain. In this way it may behave as an
extension of the user's mind and body as opposed to merely
being a remote monitoring or recording device or the like.

ephemeral criterion:
Time in processing queue (CPU) and I/O queue (user) is negligible.
In Today's computing framework, this condition can be
made even stronger:
interactional and operational delays are nonexistant,
or very small, as
the computational apparatus is
constant in both its operation and its potential for
interaction with the user.

Operational constancy:
It is always active while worn.
It may have sleep modes, but it always has the ability to
turn itself on and, for example, take notice of its environment
by virtue of some sensing apparatus (e.g. it may ``sleep'',
but it should never ``die'').

Interactional constancy:
One or more output channels (e.g. screen/viewfinder) are known
(e.g. visible) to the user at all times,
not just when the computer is being interacted with in a
deliberate manner.
In this way, context switching time to mentally engage with the
apparatus is near zero.